[Síndrome de Paget-Schrötter: presentación de cuatro casos]

Deep vein thrombosis (DVT) of the upper limb is a rare entity, estimated to account for 10% of all cases of DVT. Classically, they are classified into primary (idiopathic, due to subclavian vein compression or exercise related) and secondary (cancer, thrombophilia, trauma, shoulder surgery, associated to venous catheters or due to hormonal causes). The Paget- Schrötter syndrome is a primary thrombosis of the subclavian vein in the subclavian-axillary junction, related either to repetitive movements or to exercise; leading to microtrauma in the endothelium with consequent activation of the coagulation cascade. Clinically, it presents abruptly with pain, edema and feeling of heaviness in the affected limb. The treatment varies from thrombolytics and anticoagulation to surgical intervention, depending on the time of evolution. We present four cases of exercise-related subclavian vein thrombosis.

Management of cervical aerodigestive injuries

The management of patients with cervical injuries is highly controversial. Some authorities advocate mandatory exploration for all such injuries, while others advocate selective exploration. This paper will objectively review the evidence supporting each approach. The non-operative approach may be pursued through a variety of diagnostic modalities and this paper will also review the evidence supporting their use in cervical trauma. A clear understanding of these modalities and their relative merits is mandated by the potential severity of cervical injuries and their need for rapid intervention.

Discriminative stimulus properties of indorenate, a serotonin agonist

OBJECTIVE

To determine whether indorenate, a serotonin-receptor agonist, can exert discriminative control over operant responses, to establish the temporal course of discriminative control and to compare its stimulus properties to a (5-HT)IA receptor agonist. [3H]-8-hydroxy-2-(di-N-propylamino) tetralin (8-OH-DPAT).

DESIGN

Prospective animal study.

ANIMALS

Ten male Wistar rats.

INTERVENTIONS

Rats were trained to press either of 2 levers for sucrose solution according to a fixed ratio schedule, which was gradually increased. Rats were given injections of either indorenate or saline solution during discrimination training. Once they had achieved an 83% accuracy rate, rats underwent generalization tests after having received a different dose of indorenate, the training dose of indorenate at various intervals before the test, various doses of 8-OH-DPT, or NAN-190 administered before indorenate or 8-OH-DPAT.

OUTCOME MEASURES

Distribution of responses between the 2 levers before the first reinforcer of the session, response rate for all the responses in the session, and a discrimination index that expressed the drug-appropriate responses as a proportion of the total responses.

RESULTS

Indorenate administration resulted in discriminative control over operant responses, maintained at fixed ratio 10, at a dose of 10.0 mg/kg (but not 3.0 mg/kg). When the interval between the administration of indorenate and the start of the session was varied, the time course of its cue properties followed that of its described effects on 5-HT turnover. In generalization tests, the discrimination index was a function of the dose of indorenate employed; moreover, administration of 8-OH-DPAT (from 0.1 to 1.0 mg/kg) fully mimicked the stimulus properties of indorenate in a dose-dependent way. The (5-HT)IA antagonist NAN-190 prevented the stimulus generalization from indorenate to 8-OH-DPAT. Also, NAN-190 antagonized the stimulus control of indorenate when administered 45 minutes before the session, but not when administered 105 minutes before the session (i.e., 15 minutes before the administration of indorenate).

CONCLUSION

(5-HT)IA receptors are of relevance to the stimulus function of indorenate. However, other receptor subtypes may also be involved. Hence, other agonists and specific antagonists should be studied before definite conclusions are drawn.

Method for triglyceride measurement in small amounts of plasma

A method is described for determining triacylglyceride concentration in small amounts of plasma. After ethanolic-KOH digestion of diluted plasma aliquots, samples were neutralized with MgSO4 and glycerol was fluorimetrically assayed in supernatants by the coupling of glycerokinase, pyruvate kinase, and lactate dehydrogenase catalyzed reactions. Values were corrected by free glycerol present in the non-digested samples. Digestions were performed at different times and temperatures in order to establish optimum conditions for recoveries and reproducibility. Parallel determinations before and after phospholipid removal showed that their presence in plasma did not interfere with the obtained values. This method is especially useful for running many samples in parallel and for determinations in small experimental animals in which the amount of plasma is very limited.